[KenWittlief]

one drawback for this idea: when you have gears engaging you want the distance between the centers to be fairly precise and consistant

the gears tend to want to push each other apart

when you have a traditional gearbox, the shafts are held in a plate on bearings - they aint going anywhere

but with your idea, the mechanism that moves into place will have to be precise, repeatable, and in effect it will need to lock-in, so the gears dont push apart under heavy load.

There is a common debug problem with FIRST robots - we often get our bots working great on the table, with the wheels spinning in the air

then when we put in on the floor, and try to push something heavy, gears strip, shafts snap, motors cook.... Its hard to anticipate the secondary forces and effects that take place under a heavy load

other than that, I think if you only shift at a standstill, or when the motors are not loaded up, it should work.